Added ABI instability warning

README.md

@@ -4,6 +4,8 @@ JSON. You can then put that JSON into easy to use classes.
 
 [TODO-list](https://schlomp.space/tastytea/mastodon-cpp/milestones)
 
+**The ABI will be unstable in versions < 1.0.0**
+
 # Usage
 
 The HTML reference can be generated with `build_doc.sh`, if doxygen is installed. It is also available at

src/easy/easy.hpp

@@ -294,7 +294,7 @@ public:
      *  
      *  @since  0.17.0
      */
-    const Status send_toot(const Status &status, uint_fast16_t &error);
+    inline const Status send_toot(const Status &status, uint_fast16_t &error);
 
     /*!
      *  @brief  Base class for all entities.